Grid rows expand endlessly when theme is changed in cell merge sample

[dkalinovInfra]

When viewing the Grid Cell Merge sample (grid-cell-merge-sample) embedded in the documentation website, changing or modifying the theme causes the grid rows to expand their height endlessly, making the grid unusable.

Steps to Reproduce

1. Navigate to the Grid Cell Merging documentation page on the Ignite UI for Angular docs website https://www.infragistics.com/products/ignite-ui-angular/angular/components/grid/cell-merging
2. Observe the embedded sample with [cellMergeMode] and [merge]="true" columns
3. Use the documentation site's theme switcher to change the theme (e.g., from Material to Fluent, Bootstrap, or Indigo)
4. Observe the grid rows begin to expand indefinitely